title: Directed biosynthesis of new indolmycins.
abstract: Tryptophan in a concentration of 0.4 microgram/ml increased the production of indolmycin by 37%. The lipophilic character of indolmycin was reduced via directed biosynthesis by substituting the aromatic ring system with a methoxy or hydroxy group in the 5-position of the antibiotic. This substitution was achieved by the addition of the corresponding tryptophan and indole precursors to a growing culture of Streptomyces griseus ATCC 12648. The more hydrophilic indolmycin derivatives displayed a moderate increase in antimicrobial activity as compared to indolmycin, but did not markedly change the Gram-positive/Gram-negative ratio of activity. Thin-layer chromatography and mass spectrometry showed that additives substituted in the 6-position were not incorporated into the molecule. Antibiotic titer was reduced by addition of the modified precursors, especially in the case of the precursors substituted in the 6-position.
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001419:Bacteria / Q000187:drug effects; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007211:Indoles / Q000096:biosynthesis* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013305:Streptomyces griseus / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D007211:Indoles; C001447:indolmycin